Digital lighting technologies, i.e. illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. Some of the fixtures embodying these sources feature a lighting module, including one or more LEDs capable of producing different colors, e.g. red, green, and blue, as well as a processor for independently controlling the output of the LEDs in order to generate a variety of colors and color-changing lighting effects, for example, as discussed in detail in U.S. Pat. Nos. 6,016,038 and 6,211,626, incorporated herein by reference.
Generally, LED lighting fixtures operate to convert electrical energy to light energy. While the beam of light is cool, the fixture itself creates heat as a by-product from the energy conversion. Excessive amounts heat, when created and maintained for sustained periods of time, can damage temperature-sensitive components of the LED system. To address this issue, heat sinks are used as part of the fixture housing to draw heat away from these sensitive components.
In typical heat sink designs, a thermally conductive material, such as, for example, aluminum, is cast or formed into a shape that is designed to transfer heat away from the electronics to the exterior of the fixture by means of, for example, conduction, convection, and radiation. To maximize heat transfer, heat sink designs aim to have the maximum amount of surface area possible while permitting for sufficient air flow. Areas on the heat sink that enable air flow can aid in natural convection and can provide areas for forced air to travel. For example, wind, which can create forced convection, can travel through these areas of the heat sink. These designs aim to maintain the temperature of the electronics to a sufficient level that can extend the lifetime of the fixture.